Hydrophobic fabrics of polyester or polyamide, for example, or else blend fabrics with cotton, in the course of their production, are post-treated in aqueous liquor with hydrophilizing agents and conditioning agents, in order to finish the fabric such that it is pervious to damp air—that is “breathable”—and retains its shape, in conjunction with a good soft hand.
Reactive prepolymers, such as amino-functional and epoxy-functional polyether siloxanes, for example, can be cured with one another on the fiber to form high molecular mass coatings, as described in U.S. Pat. No. 4,659,545 A1, for example. Efficient, uniform application of the hydrophilic reactive polymers into the fiber, and quantitative reaction of the components are difficult to control. Many of these amino silicone emulsions lack temperature stability, and the resulting hydrophilization may therefore be uneven. This unevenness is manifested on the textile, after the subsequent dyeing operation, by phenomena such as oil spotting, for example, leading to these goods being rejected.
Frequently used are emulsions comprising aminosiloxanes or silicone quats as their active component (Roulette: Handbuch Textilveredelung [Textile Finishing Handbook], Volume II, 14th edn. 2003, 304 ff). The emulsifier used for the emulsification, generally a fatty alcohol ethoxylate, likewise goes onto the textile surface and partly displaces the active component or prevents it from anchoring to the fiber, meaning that conditioning is not efficient. Leaching of the emulsifier and of the inadequately anchored active component during the first few times the textile is laundered is very soon unmistakeable, since the garment suffers impaired tactility. Moreover, the additional use of emulsifiers leads to increased migration into the fibers. The result of this is not only a loss of active substance but also an increased tendency for slippage of the fibers relative to one another. This is manifested in reduced dimensional stability on the part of the completed textile.
When sufficiently hydrophilic, more hydrophilic siloxane-polymer copolymers containing amino groups or cationic groups, such as, for example, the linear ABn block copolymers described in US 2012-0308494, CN 102199295, KR 2009130695 and U.S. Pat. No. 5,807,956, or pendant or terminal aminosiloxanes functionalized with monoepoxy polyethers and described by way of example in US 2005-0053570 or EP 1477513 A1 (US 2004-0225099), can be formulated without emulsifier. Nevertheless, because of their increased hydrophilicity, they are not so good at depositing on the textile. The anchoring on the textile surface is primarily adsorptive and less permanent, since the secondary and tertiary amino groups are sterically hindered and insufficiently reactive for interaction with the polyester groups. High molar masses are required, which go hand in hand with high viscosities and greater formulation difficulties in order to reduce inevitable leaching to an acceptable degree.
SiOC-aminopolyethersiloxanes are out of the question on account of instability to hydrolysis, undergoing breakdown even in the liquor before they deposit on the textile, and being decomposed more quickly than SiC-functional siloxanes, at the alkaline wash stage, if not earlier (cf. WO 200961362).
Possessing a much more strongly pronounced silicone character, in contrast, are cationic silicones, of the kind described in EP 0 294 642 (U.S. Pat. No. 4,891,166). EP 0 294 642 describes structures where the quaternary functions are bonded terminally to a siloxane segment. When a textile is treated with such compounds, it does indeed acquire a good soft hand, but the low substantivity of the siloxane means that it is easily removable from the corresponding textile again, as a result of laundering procedures, for example. Furthermore, compounds of this kind can be adequately fixed usually only on natural fibers. In contrast to the household fabric softener, however, it is desirable, for industrial OEM textile finishing, for the siloxane to remain on the textile even after laundering and hence for the soft hand to be maintained.
All of the prior-art finishing compositions for hydrophilization have the disadvantage of an inadequate dimensional stability.